This is the bug/patch tracker for Rockbox. Click here for more information.
Quick links: Bugs · Patches · Rockbox frontpage
FS#8651 - Screeching, High-Pitched Noise after Crossfade
Attached to Project:
Rockbox
Opened by Humberto Santana (hhannah) - Tuesday, 26 February 2008, 21:10 GMT+1
Last edited by Andree Buschmann (Buschel) - Sunday, 30 March 2008, 12:17 GMT+1
Opened by Humberto Santana (hhannah) - Tuesday, 26 February 2008, 21:10 GMT+1
Last edited by Andree Buschmann (Buschel) - Sunday, 30 March 2008, 12:17 GMT+1
|
DetailsTHIS IS A DIFFICULT ONE!
First, I must say that I've found this bug VERY difficult to report, because although quite frequent, it is VERY "slippery" (maybe attempted to be described in the past many times (see [*] below) - from what I found in the flyspray & forums) I kind of feel like a ghostbuster here!. I've been "coexisting" with it since I installed Rockbox in November/07. It is related to crossfading, which I use all the time (main reason for coming to Rockbox!). I will do my best to give the relevant information I've found, and also, I kindly request experts' help/ideas on what to check/try in order to find the causes with more accuracy, if that's necessary in addition to the information I present, in order to solve the bug (please notice that this is NOT a support request!). - iPod video 80GB 5.5G - rockbox r16422 (but also happened in previous versions, at least from November/07 to this version) - mp3 format (both in variable and constant bitrates) *Description* Eventually, shortly after crossfading (or right during the crossfading process), playback stops advancing and a screeching, high-pitched, almost hurting, repeating noise begins. I've attached a recording of the problem so that you can actually hear it (sorry about the sound quality, I didn't find a better way than a mic). Other functions seem to keep on working normally during this noise problem (wps info, menu browsing, etc). To stop the noise, I've used the Prev on the clickwheel, and the current song re-starts ok. If I attempt a forward skip, the noise continues. If I pause, and then resume, the noise continues. If I reboot, when going back to "now playing", it resumes OK but in the previous song to the bug, close to the end of that song. *To Reproduce* Now THIS is the main difficulty with this bug, I haven't found a way to reproduce it precisely (I've invested a lot of time in this, but all I've got is what's describe here). I just use crossfading continuously, and sooner or later, the bug appears. In order to give more information about this, I took two actions. 1. I checked the view options in the "debug menu", and 2. I've tried different setting combinations, discarding possible causes. 1. In the debug menus, I've noticed the following: - In the "View buffering thread" option, the pcm bar/values rise almost to the top and stay there during the noise. In normal operation, it goes down after the crossfading process. Also, the CPU freq is 30Mhz during the problem. Typical values on this screen during the problem are (values vary slightly from bug to bug): pcm: 3170592/3175200 alloc: 56297688/60322272 real: 54987063/60322272 userfl: 394555113/60322272 data_rem:4567692 track count: 6 (has happened with values 0 to 7, so far) handle count: 21 (has happened also with i.e values of 18) cpu freq: 30Mhz (always ends with that value when the bug occurs) boost ratio: begins with 100% when the problem starts, goes down gradually to 0%. Is the THIS IS THE ONLY VALUE ON THIS SCREEN THAT CHANGES DURING THE PROBLEM, THE OTHERS REMAIL STATIC. pcmbufdesc: 92/129 - In the CPU Frequency option (debug menu), the values during the bug are: (ALWAYS) Frequency: 30000000 boost_counter: 0 2. Discarded possible causes Given that crossfading is enabled (different fade-in and fade-out durations, fade-in delay set to 0, fade-out delay set in tests to a value > 0, fade-out mode set to crossfade), I've tried different combinations for the following settings, but since the bug occurs with or without these settings, I guess they can be discarded as possible causes: - Equalizer enabled or disabled, different specific values. - All the other "sound settings" were always in their default values. - Replaygain enabled or disabled, any mode, clipping enabled or disabled, pre-amp any value. - Any mp3 bitrates (different kbps and/or variable-constant rates in songs involved during crossfading) - Shuffle enabled or disabled, any mode. - Repeat enabled or disabled, any mode. - All the other "playback settings" were always in their default values. - Any wps loaded (just in case the theme .cfg could have some effect) [Also in the attachment a typical .cfg] 3. Additional information Because I can't be 100% sure that the following information relates to the bug, and because this doesn't happen ALL the times the problem occurs, I just put it here in case it gives someone a clue: After the problem occurs: - Sometimes after normal playback is restored, crossfade doesn't work anymore. At the end of the song it sort of begins the crossfading process, but the songs are not mixed finally. - Sometimes the iPod crushes when operating it after the bug restore, the screen is the theme's wps .bmp, the text displayed "Undefined Instruction at 00069DC4 (0) [code's last 3 digits vary] - Sometimes browsing and normal menu operation becomes very, very slow Thanks in advance! And if there is something else that I can do to help, please just let me know. ---------------- [*] THESE SEEM TO REFLECT THE SAME PROBLEM: http://forums.rockbox.org/index.php?topic=3860.0 http://forums.rockbox.org/index.php?topic=15406.0 http://forums.rockbox.org/index.php?topic=8946.0 http://forums.rockbox.org/index.php?topic=6281.0 Similar reports (but most probably not the same?): http://forums.rockbox.org/index.php?topic=8335.0 
ScreechingNoiseIn Crossfading.zip
(1.38 MiB)
|
This task depends upon
Closed by Andree Buschmann (Buschel)
Sunday, 30 March 2008, 12:17 GMT+1
Reason for closing: Fixed
Additional comments about closing: Committed with #16889 and #16890.
Sunday, 30 March 2008, 12:17 GMT+1
Reason for closing: Fixed
Additional comments about closing: Committed with #16889 and #16890.
In my case, it happens almost 30 mins or so after starting up rockbox (i.e. ipod is turned on).
Today I decided to take crossfade out, and the iPod has been playing all morning with no problems at all.
I'd guess that this may be related to the problem where keyclick is played as a beep/horrible screech noise on PortalPlayer targets. Maybe someone with a suitable target could perhaps enable keyclick and get debugging pcm-pp.c?
@pondlife: For what's worth, I always have Keyclick=Off and Keyclick_Repeats=No
I did the test in two ways, a) enabling keyclick settings and then waiting for the bug to happen, b) having keyclick settings disabled, and enabling them when the bug happened... but (unfotunately?) in both cases no key or scrollwheel action generated more noise (or less); the noise-silence cicle that repeats wasn't increased, interrupted or modified at all
:(
My experience: I've been getting this periodically on 2 separate 60GB 5g ipods ever since I first installed Rockbox back in '05. Like..maybe a half-dozen times a year, well.. up until recently--it's hard to quantify, but my subjective perception is that the probability of it happening has definitely increased sometime in the last few months. It's been something that I've never worried about precisely because it's so random and because it seemed like no one else was experiencing it. Not sure what will happen but thanks for making the report hhannah. :)
I wish I was as lucky as you, only getting the problem once in a while, but the thing is I use crossfade ALL the time, so I get the noise quite often. The question for you would be how often do you use crossfade, and how long are the listening on crossfade periods. For example, if someone uses only "crossfade when track skipping", and she only skips songs a few times, crossfading occurs only a few times and not one song after the other... that would be something quite different as listening music for 2 hours continously, using crossfade set to always.
@ Bookshare: as you say, I didn't find reports from people using other DAPs
The battery will run down much faster when the CPU is boosted, so you may need to run powered too.
I'm doing what you suggest... still testing (so far results are not so clear)... I'll let you know when I do this longer
The crossfade problem, most likely, changed on a recent version. What happens now is that the iPod crushes during the crossfade process, freezing up and just showing "Data abort at 40000250 (0)" or "Data abort at 400002E0 (0)". THE SCREECHING NOISE, THOUGH, HAS APPARENTLY DISAPPEARED. Therefore, people that experience the crossfade problem from now on, might not identify it with this task.
The last version that I used experiencing the noise problem was r16507, but then I just jumped to version r16717, and since then the crossfade problem changed as I explained, even in the current version that includes viewports, etc.